Question

A machine takes $2$ litres of petrol to start and then $3$ litres per hour while running. What will the no. of hours for which machine run if total $20$ litres of petrol is used?

• A. $4$
• B. $5$
• C. $6$
• D. $8$

Answer 1

Answer: (C)

$6$

No. of liters of petrol to start the machine $=2l$

No. of liters of petrol per hour while running $=3l$

Fuel consumed to start + Fuel consumed to run for $n$ hours $=20$

$\Rightarrow 2+3n=20$

$\Rightarrow n=6$